div {
    width: 300px;
    height: 300px;
    
    display: flex;
    justify-content: space-between;
}
div > div {
    display: block;
}
b {
    width: 100px;
    height: 30px;
    border: 2px black solid;
    display: flex;
    justify-content: center;
    align-items: center;
    
}
.a1 {
    text-decoration: none;
    color: blue;
}
.a2 {
    text-decoration: line-through;
    color: green;
}
a {
    color: red;
}